408 G. HERBERT FOWLER. 
also entirely normal. No zooxanthelle occurred in this 
specimen. 
From the foregoing description it is sufficiently obvious 
that Duncania is a true Madreporarian, differing in no point 
of importance from the ordinary type; a fact interesting, 
since Pourtalés, who founded the genus,! regarded it in the 
first instance as a living member of the great Order M adre- 
poraria rugosa, which characterises Carboniferous strata, 
basing this belief chiefly on the tetramerism of the septa. 
Both he? and Lindstroém,? in pointing out independently that 
tetramerism is not an embryonic character of these corals, 
have really brought Duncania and the so-called Rugosa into 
closer alliance. While Lindstrom writes, “There seems to 
be no reason to class this species”? (Duncania) “among the 
Rugosa, which commonly are considered to have four septa 
of the first order. In making a thin section of the apex 
of a Duncania I distinctly saw six septa of the first order, 
which meet in the centre ;’—Pourtalés points out that he and 
Ludwig (‘ Paleeontographica,’ x and xiv) have independently 
arrived at the conclusion that the young “ Rugose” coral 
(in this instance, Lophophyllum proliferum) has at first 
six primary septa, and that the apparent tetramerism is due to 
arrest of two of the primary hexameric systems. If therefore, 
as seems probable, it be ultimately proved that Duncania is 
allied to such forms as Zaphrentis, it is most interesting to find 
that the latter are really to be assigned to the Madreporaria, 
a conclusion on which serious doubt has been cast. 
In spite of the fact that there are two genera of Corals 
bearing the name Duncania, and both are usually classed with 
the ‘‘ Rugosa,” I have not ventured to rename Pourtalés’ form, 
since it appears to be doubtful whether the other (and prior) 
1 « Deep-sea corals ” in ‘Mem. Mus. Comp. Zool. Harvard,’ vol. iv, 1874 
(= ‘Zool. Results Hassler Expedn.,’ pt. i, ‘‘ Echini, Crinoids and Corals”’). 
2 In a discussion of Haplophyllia, a close ally of Duncania, and, like it, 
classed with the Rugosa, ‘Mem. Mus. Comp. Zool. Harvard,’ vol. ii (= 
‘Tilustr. Catal. Mus. Comp. Zool. Harvard,’ No. iv). 
3 «Contributions to the Actinology of the Atlantic Ocean,” ‘ K. Svensk. 
Vet.-Akad. Handl.,’ xiv, No. 6, p. 13. 
